Why can PUT and DELETE affect multiple objects? This is massively frowned upon in typical REST conventions.

Query string is always stringly typed, but the objects can have types other than strings (such as id). It is not specified how filtering should handle values of different types.

The design of this kata inflates the notion of an object with no properties and a missing object. What exactly does "an empty object" (as the kata calls it) mean? {} is also a valid object, so there must be another criteria to determine what is empty. Meanwhile, this payload makes no sense whatsoever as it means you're passing in invalid objects as the body (instead of not passing in objects), and GET/DELETE can't ever have request body so payload shouldn't even be an object. This design doesn't make sense.

isn't that a duplicate of this? https://www.codewars.com/kata/56113aaacc951d7488000001 (edit: mmh, the present one seems a bit simpler)